China’s biggest political crisis in a generation has claimed another high-profile victim after Li Xueming, the businessperson brother of fallen politician Bo Xilai, stood down from his executive roles at the Hong Kong-listed financial firm China Everbright International, after media reports shed light on his personal background.

In a statement, the company – whose head company is the state-owned China Everbright Group – said Li had decided to resign as director and vice-chair ”in order to minimise any possible adverse impact on the company of certain reports recently published by the media on his family background”.

The company said last week it would verify the identity of Li, after the Chinese language Hong Kong newspaper Apple Daily reported he was using an alias and was in fact Bo Xiyong, the elder brother of Bo Xilai.

Li has cashed out on $HK43.2 million ($5.6 million) worth of shares in the past two years, and has an annual salary of about HK$1.7 million.

The revelations come amid a defiant statement by Bo Xilai’s son, Bo Guagua, to the Harvard University’s newspaper to express his ”deep concerns” over the events surrounding his family, including intensifying investigations into the Bo family’s wealth and business dealings.

He said he had ”never lent my name to nor participated in any for-profit business or venture, in China or abroad”.

But investigations have revealed a business empire operated by the sisters of Gu Kailai is worth at least $136 million, while the total Bo family assets could be worth considerably more. There are allegations Gu’s successful law firm could have acted as a conduit to divert funds to her sisters’ enterprises. Bo Guagua’s half-brother, the 34-year-old Li Wangzhi, from Bo Xilai’s first marriage, also has wide business interests spanning across China, the US and Mauritius.

Bo Xilai was sacked as Chongqing’s party secretary last month. His wife, Gu Kailai, has been detained on suspicion of murdering the 41-year-old British national Neil Heywood.

Bo Guagua, 24, a postgraduate student at Harvard’s Kennedy School of government, said he had no comment about the concurrent investigations into his parents, but felt ”responsible to the public to provide an account of the facts” surrounding his private life.

The ability of Bo Xilai, on his modest official Communist Party salary, to fund his youngest son’s expensive education, which also includes stints at Harrow and Oxford, has long been called into question.

Widespread reports in November that Bo Guagua had arrived in a red Ferrari at the Beijing residence of a former US ambassador, Jon Huntsman, for a function, fuelled further speculation that his display of wealth was just the tip of iceberg of Communist Party corruption and a lifestyle of excess enjoyed by the children of senior party members.

But Bo Guagua said the reports were false. ”I have never driven a Ferrari… nor have I ever been to the US ambassador’s residence in China.”

He said his tuition and living expenses had been funded by scholarships and from his mother’s savings.